Pivoted test clamp



ROGERS pril 14, 1953 PIVOTED TEST CLAMP Filed June 18, 1947 lllill w! myW W w W a y y M W #w 6 97% W5 y d NV u 92% w W 1 A 7 W 2 V Z 4 \lzl 51,?3/2 A TORNEYS,

Patented Apr. 14, 1953 PIVOTED TEST CLAMP Robert W. Rogers, Harrington,It. I., asslgnor to Scott Testers, Inc., a corporation of Rhode IslandApplication June 18, 1947, Serial No. 755,531

3 Claims.

, 1 This invention relates to a clamp for gripping a specimen to betested and more particularly -to a clamp usually referred to as a toggleclamp.

Clamps of the character here referred to provide movable jaws which areeach hung upon a pair of links to move in parallel relation as the jawmoves relative to the part to which the links are connected. The linkscannot properly function at an angle higher than 20 to a perpendicularto the face of the jaws as the proper clamping action is not obtained.Thus, such a clamp has a very limited range as to the thickness of aspecimen which may be received in the clamp. It is desirable that thelinks which mount the jaws be at approximately 10 to a perpendicular tothe jaws'in order that the best gripping action at maximum pull may beprovided for. It is also desirable that the specimen clamped shall be onthe center line of pull on the clamp in order that irregularities due toangular direction of pull may be minimized or eliminated.

One of the objects of this invention is to provide an adjustment for thejaws which will enable a single clamp to have a larger range of capacityfor engaging work of different thick nesses.

Another object of this invention is to provide an adjustment which maybe calibrated and marked so that the jaws may be preset for differentthicknesses or for different types of specimens.

Another object of this invention is to provide an adjustment which maybe provided very accurately by reason of the rotation of a member toposition the blocks.

With these and other objects in view, the invention consists of certainnovel features of construction as will be more fully described andparticularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a top plan view of the clamp;

Fig. 2 is a central sectional view through the clamp;

Fig. 3 is a section on line 3-3 of Fig. 2;

Fig. 4 is a fragmental detailed view illustrating the connection betweenone of the jaws and one of the blocks of the clamp.

In proceeding with this invention, I provide a body of a general framestructure which has guide ways formed in it for directing the movementof a pair of blocks toward and from each other. Each of these blocksprovides an anchor or mounting means for one of the gripping jaws forthe work, the jaws being pivoted to the block by two pairs ofvparallelly arranged links. The arrangement is such that, when the workis gripped by the jaws, the links will be at an angle tola'perpendicular to'the, face of the jaws so that, as" pull occurs on'thejaws, the jaws will tend to swing the links and will move toward eachother into firmer gripping relation. The blocks are adjustably mountedin the body so a different spaced relation of the jaws may occur, theadjustment being by means of rotary members, such as an eccentric, whichwill extend through the block with the eccentric working in a recess inthe block for engaging the opposite walls of the recess to move theblock in its guide for the accommodation of different thicknesses ofspecimens and a calibration is provided so that 'at different positionsof rotation specimens of different thicknesses may be noted.

Each of the jaws may be provided with an ejecting pin, and the jaws maybe equipped with a means so that through a single handle both jaws aremoved together by one hand of Guides for positioning the work" theoperator. may be conveniently positioned in the clamp.

With reference to the drawings, the body of the clamp is designatedgenerally l and comprises a pair of plates H and I2 which are sup.-ported in spaced relation by means of spacing members l3 placed alongthe longitudinal edges of the plates II and I2 and provide with the Eachof the blocks has a vertically extending recess providing oppositeabutting walls 21 and 22. A shaft 23 has a bearing 24 in the plate H anda bearing 25 in the plate l2, and

on this shaft there is an eccentric 26 which en-. gages the oppositesurfaces 2| and 22 of the recess so that as the shaft 23 is rotated theblock IE will be moved inwardly or outwardly of the framework or bodyl0. Springs 21 support the blocks IS in a position raised above thelower plate 12, while the blocks slide in the guide ways M which directtheir in and out movement. A disk 30 is keyed to the shaft 23 and maymove vertically along this shaft and is pressed upwardly by a spring 3!when released by the thumb nut 32 which has threaded engagement as at 33with the shaft 23. A spring ring 34 prevents this nut from beingaccidentally lifted too high on the shaft.

A second disk 35 is positioned beneath the disk 30 and beneath thisthere is a dial or grad-- uated plate 36. Both the disk 35 and the dialplate 36 are secured to the plate II by means of screws 31. The upperannular edge of the plate 35 and the lower annular edge of the plate '30are provided with serrations, as shown at. 38in Fig. 2, so that when.these disks are movedtogether by reason of the thumb nut 32 the shaft 3is locked in position. Thus, for adjustment of the block 15 it isnecessary to loosen the nut 32 which permits the spring to raise thedisk 30 'along its key way, thus permitting the shaft to be turned untila pointer 39 registers with the proper indication on the graduated dial36. Then'.

45 comprising a horizontal plate 46 and two. in-,

clined plates 47 spacing the plate 46 a distance above. the; plate ll.this. plate 66 having; a threaded: socket se for the reception of anattaching rodrupon which pull,.or: resistance to pull on the other endof the; specimen may be applied. The under: surface 51 f this. bridgemay serve as. ameans for. limiting or 'guidingone, end of the, specimeninto.-

a desired position between the clamping jaws.

The clamping jaws. are designated 52. and consist. of a T-block53havinga, separabl face member 54' with serrations. thereon which may beattached by. means. of-screws 35. to the, block 53. A spring-pressed.pin 56. is. slidable in the block and facing member andis pressed by aspring, 58. outwardly and is limitedinits movement. by the. facingmember 54. engaging, the shoulder. formed by. the. head 51 onth pin 56.Each ofthese. jaws. 52 is. attached'to one ofthe. blocks: 15 by links69. and 61 arranged. in: parallel relation. and pivoted as:at.-62. and63. to the block: andas at. 6111 and: 65. to. the. jaw. Theseparallelly. arranged linksare. provided both at.

thefront and back edgeof. the jaws and. blocks.

One of. the pivotscomprises. a.. shaft 66. (see,

Fig. 3) whichpasses throughone ofthe blocks and. has itslink, such a561,fixed t the shaft. Thisshaftis also provided with a lever: 6-! act.-

ing' asahandlewhichis securedlin place on the.

shaft by anut 68 .so that movementof' this lever to: difierent positionswill serve to swingv the. link fil' and by reason of: the connectionsabove.

mentioned also the link 611 to movethe'jaw. to.- wardand fromlacenterline throughtheclamp.

Inorder that both. jaws may be moved at,

th'e same time, I' providea bar 69.secured.to.the

jaw: which is equipped. with the handle as by. means of a screw 19:whichbar is slidably related to the other jaw in guides H so thatas, onejaw israised theother jaw will also be. raised and-thus will swingtoward and. from the.

center .of the clamp alike amount. This bar alsomay be a means forlimiting: the insertion of the. work between the jaws by acting as. a

, back guide in instances where desired.

Fromthe above, it will be apparent. that. I have. provided a pair of.jaws which will remain centralized. with reference to. the;pul1 rod, insocket49. at all timesif the. blocks which carry themare. once.adjustedto: equalpositions from the center line.

The blocks may be adjusted in smallincre- This is a feature which isparticularly useful jnvtestinga sample in which thetwo gripped faces.

A; boss 48. 15 provided on 4 have different surface characteristics ofcompressibility and which by this oiT-center adjustment enables thesample? to be-- kept 1 centralized. Each block may beeaccurately. set byits. dial 1 moving under pointer 39 and will be held in position by theserrations beneath the plate.

When. it. is desired to release the jaws from gripping position whichthey will assume as the work ispulled; it is merely necessary to movethehandlefi'! by one hand for lifting the jaws and releasing the work.As the work is released, the spring. pins will eject the work from theaws.

When used in a testing machine, two of these clamps, one upside down"with the plate l2 at theto as here shown, are. utilized; togrip thespecimen.

I claim:

1. In. a clamp. for; gripping. a specimen. for testing or the: likevhaving a body,, a, pair of. hole. low blocks slidablyguided insaid'body, appair of, gripping jaws, links movably-mountingsaid jawswith reference tosa-id. blocks; meansifor adjust: ing. the position ofat least: oneof saidblock comprising a rotatableshaftextending through.the said one block, means carried,bysaid,shaft, and extending intoengagement with th inner. Walls of said one block for; mcving thevsameztowards or from said jawss uponturnin said; shaft, an abutment carried;by; said body; an. abutment slidably mounted onJsaim shaftand movableinto enga ement. with the. first: said abutmentfor lockingsaid-shaftagainst turm ing, and resilient means:- biasinggsa id...second; abutment for movement: awa efrom. said, first. abutment. V

2. In a clamp as set forth in claim 1 wher in. said first abutment. is;a. serrated. disk. fixed. on said body and said second: abutment is asime ilar disk slidably mountedion-saidishaft.

3. In aclamp as set forth inclaim. 1': further.

comprising a pointer carried by the secondsaid: abutment movable over. agraduateddiskifor 'ine di'cating the adjustablepositiontof said oneblock:

ROBERT ROGERS;

References Cited in the: fileofsthismatenti UNITED STATES PA'I'ENTSNumber Name Date.

273,195 Utter Feb;v 27, 1883 600,535- Homan Mar, 15, 896:. 675,047MacGarvey .May=2&,.199.1 749,732 Hanson Jan; 19;.1904. 824,000 Elmer sJ1me; 19;.l 05 920,820 Brown. 4; 19.09

1,051,585: Hiniker." Jan. 28",. 1.913 1,127,066 Minkler Feb. 2, 1915-:1,292,930 Unger. Jan. 2 8;; 1919 1,566,006: Hiniker ...Dec. 15; 19251,692,398 Weaver ".Nov. 2 0,.1928; 1,762,037 Taylor; ...J.une;3, 1930:1,837,990 Otis- Dec. 22,1931 1,981,304. Brandt Nov. 20, 1934 1,982,482Rhodes. Nov, 27,1934, 2,114,305 Johansen Apr. 19., 19 38 2,173,079.Moody se t..12, 19.39:, 2,417,478 Flowers Mar .18, 1947. 2,462,536 MuterFeb; 22., 19.49;

FOREIGN PATENTS Number Country. A Date 285,389 Germany -1--. Apr. .24;,191'4. 482,984 Great, Britain e. Apr... 8,' 19.38,?

